package Volume1.ch10;

import javax.swing.*;
import java.awt.*;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Line2D;
import java.awt.geom.Rectangle2D;

/**
 * 10-4: 1.绘制一个矩形，这个矩形内接椭圆;
 *       2.绘制矩形的对角线以及以矩形中心为圆点的圆
 *
 * @Auther jacob
 * @Date 2020/8/16 01:14
 */
public class DrawTest {
    public static void main(String[] args) {
        EventQueue.invokeLater(()->{
            JFrame frame = new DrawFrame();
            frame.setTitle("DrawTest");
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            frame.setVisible(true);
        });
    }
}

class DrawFrame extends JFrame{
    public DrawFrame(){
        add(new DrawComponent());
        pack();
    }
}

/**
 * A component that displays rectangles and ellipses.
 */
class DrawComponent extends JComponent{
    public static final int DEFAULT_WIDTH = 400;
    public static final int DEFAULT_HEIGHT = 400;

    @Override
    public void paintComponent(Graphics g){
        Graphics2D g2 = (Graphics2D) g;

        // 绘制长方形
        double leftX = 100;
        double topY = 100;
        double width = 200;
        double height = 150;

        Rectangle2D rect = new Rectangle2D.Double(leftX, topY, width, height);
        g2.draw(rect);

        // 绘制内接椭圆
        Ellipse2D ellipse = new Ellipse2D.Double();
        ellipse.setFrame(rect);
        g2.draw(ellipse);

        // 绘制对角线
        g2.draw(new Line2D.Double(leftX, topY, leftX + width, topY + height));

        // 绘制一个同心圆
        double centerX = rect.getCenterX();
        double centerY = rect.getCenterY();
        double radius = 150;

        Ellipse2D circle = new Ellipse2D.Double();
        circle.setFrameFromCenter(centerX, centerY, centerX + radius, centerY + radius);
        g2.draw(circle);

    }

    @Override
    public Dimension getPreferredSize() {
        return new Dimension(DEFAULT_WIDTH, DEFAULT_HEIGHT);
    }
}
